The present disclosure is related generally to the fabrication of semiconductor devices, and, more particularly, to a metal-insulator-metal (MIM) structure, a method of manufacturing the structure, and a semiconductor device incorporating the structure.
Capacitors are critical components for many data manipulation and data storage applications. In general, capacitors include two conductive electrodes on opposing sides of a dielectric or other insulating layer, and they may be categorized based on the materials employed to form the electrodes. For example, in a metal-insulator-metal (MIM) capacitor, the electrodes are substantially metal. MIM capacitors offer the advantage of a relatively constant value of capacitance over a relatively wide range of voltages applied thereto. MIM capacitors also exhibit a relatively small parasitic resistance.
Generally, it is desirable to maximize capacitance values of MIM capacitors. In this regard, capacitance values for a single capacitor generally increase as the surface area of the capacitor electrodes increases. However, when multiple MIM capacitors are utilized across multiple applications on a single semiconductor substrate, it is difficult to both maximize capacitance and fabricate the capacitors in a compatible manner. For example, MIM capacitors may be employed for both data retention in dynamic random access memory (DRAM) applications and decoupling in mixed-signal and microprocessor applications. In such a situation, chip designers strive to strike a balance between maximizing capacitance in each application and minimizing the number of process steps required to simultaneously fabricate the capacitors. Although multiple-application MIM capacitor designs have been generally satisfactory, they have not been satisfactory in all respects.